1. Field of the Invention
This invention relates to a robot apparatus of the type walking on two feet, such as human being, performing autonomous operations simulating the bodily mechanism or movements, and a method for controlling the movements. More particularly, it relates to a robot apparatus having the function of estimating the sound source direction and performing the movement of turning to the sound source direction by a concerted full-body movement, and a method for controlling the movements. This application claims priority of Japanese Patent Application No.2002-075147, filed on 2002, the entirety of which is incorporated by reference herein.
2. Description of Related Art
A mechanical apparatus for performing movements simulating the movement of the human being, using electrical or magnetic operation, is termed a “robot”. The robots started to be used widely in this country towards the end of the sixtieth. Most of the robots used were industrial robots, such as manipulators or transporting robots, aimed at automation or unmanned operations in plants.
Recently, development in practically useful robots, supporting the human life as a partner, that is supporting the human activities in various aspects of our everyday life, such as in living environment, is progressing. In distinction from the industrial robots, these practically useful robots are endowed with the ability to learn for themselves the method for adaptation to the human being with variable personalities, or to variable environments in variegated aspects of our everyday life. For example, pet-type robots, simulating the bodily mechanism or movements of animals, such as quadruples, e.g., dogs or cats, or so-called humanoid robots, simulating the bodily mechanism or movements of animals erected and walking on feet, such as human being, are already being put to practical use.
As compared to the industrial robots, the above-described robot apparatus are able to execute variable entertainment-oriented operations, and hence are sometimes called entertainment robots. Among these robot apparatus, there are those operating autonomously responsive to the external information or to the inner states of the robot apparatus.
It should be noted that the robot apparatus, performing the autonomous operations, owns the function of recognizing the information of the outer world to reflect the so recognized information on its own behavior. That is, the autonomous robot apparatus changes the feeling model or the instinct model, based on the input information, such as the speech or pictures from outside, or the tactile sense, to decide on its behavior to achieve autonomous thinking and operation control. By the robot apparatus owning the feeling model or the instinct model, the communication between the human being and the robot apparatus may be achieved on a higher intellectual level. It may be surmised that the communication between the human being and the robot apparatus will be smoother if the robot apparatus is the ‘humanoid’ robot, that is of the same shape or the same structure as the human being.
It may be said that movements closer to those of the human being would be realized with the ‘humanoid’ robot apparatus if, when the speech is input from the outside environment, the robot apparatus directs itself to the sound source to try to recognize the environment. In particular, from the perspective of improving the friendly relationship with the human being, it is more desirable that, when a person accosts to the robot apparatus, the robot apparatus direct its face to the accosting person.
However, with this ‘humanoid’ robot apparatus, the possible range of movement of for example the neck or the body trunk portion is limited to improve the impression of the robot apparatus as if it is a living being. That is, if the speech is input from the back side, the robot apparatus is unable to rotate its head in an unlimited fashion. It is therefore desired that the robot apparatus performs a turning movement close to that of the human being.